Human use of Ecosystems

1. Human use of Ecosystems People have the responsibility to regulate their impact on the sustainability of ecosystems in order to preserve them for future generations.

2. Lessons From Easter Island

3. Human well-being depends upon ecosystems. • Ecosystems provide food, fuel, natural resources, and water. • Ecosystems cycle nutrients and decompose wastes.

4. Human well-being depends upon ecosystems. • They regulate climate. • The animals they contain help pollinate crops and disperse seeds. • Ecosystems also provide humans with cultural and recreational opportunities

5. Biodiversity What is Biodiversity? • Biodiversity is the type and number of different organisms that live in an ecosystem. • More is ALWAYS better!!

6. Why is biodiversity important? • Each of the species contained in ecosystems contribute to the services that are important to human well-being. • So we all have a vital interest in maintaining biodiversity,

7. Sustainable use • Sustainable use of an ecosystem means using an ecosystem’s resources in a way that meets our current needs without compromising the ability of future generations to meet their needs.

8. Levels of Biodiversity There are 3 levels of biodiversity: • the variety of species on Earth • the diversity among a species – the different genetic make-up of the individuals or genetic diversity • The variety of ecosystems on Earth or ecosystem biodiversity

9. Genetic Diversity • Why is genetic diversity important?

10. Genetic diversity • Genetic diversity among a population of organisms is important because each individual is unique and has different abilities and strengths that keep the population healthy and strong. • Some individuals have different immunities to disease or may be better at tolerating a lack of water

11. Ecosystem Diversity • Human-made ecosystems include: • farms • cities • parks • Different ecosystems provide us with different services

12. Human influences on biodiversity • Human activities have caused a tremendous decline in biodiversity. • What kind of activities?

13. 5 main causes of decreased diversity • habitat change • overexploitation • pollution • invasive species • climate change

14. Habitat Change • Habitat change is the process by which humans alter a habitat enough so that the native species can no longer live there. • Native species are species that normally live in that habitat • Habitat change is the most common cause of declines in the populations of many species

15. Overexploitation • Overexploitation of a resource means using a resource faster than it can be replaced. • Overexploitation can often lead to extinction. • Overexploitation of the seas is one of the greatest environmental catastrophes in human history.

16. Overexploitation of cod

17. Overexploitation of water • Fresh water is the most precious resource • Canada has the most fresh water in the world. • Canada is working on ways to sustainably manage it

18. Aral Sea The Aral Sea was once the fourth largest fresh water lake

19. Aral Sea 2007 1985

20. Pollution • Pollution is any substance added to the environment that produces a condition that is harmful to organisms. • Solid waste – garbage • Air pollution – CO2 produced by cars • Water pollution – oil spills and waste water

21. Point Source Pollution • Point source pollution enters a body of water at a specific place from an identifiable source. • oil spills from tankers • waste water from pulp and paper mills

22. Point and Non-point Sources of Pollution

23. Non-point Source Pollution • Non-point source pollution enters bodies of water indirectly when water from rain or snow travels over land and picks up pollutants from many different sources • fertilizer and pesticide run-off from farms • salt runoff from roads

24. Invasive Species • An invasive species is a non-native species that causes harm to the ecosystem into which it has been introduced. • Invasive species tend to outcompete native species, often because they have no natural predators in the new ecosystem or they reproduce faster than native species.

25. Climate Change How will climate change affect these walrus?

26. Climate Change • Climate is the average weather conditions that occur in a region over a span of 30 years or more • When climate change occurs… • average temperatures may rise or fall • the amount of rainfall may increase or decrease • general wind directions may change.

27. Global warming • Global warming is an increase in Earth’s average temperature • It is caused partly by an increase in carbon dioxide in the atmosphere • The amount of carbon dioxide in the atmosphere has increased largely due to human activities that burn fossil fuels

28. Human disruptions and the effects on the ecosystem • A road is built through a forest • A factory puts pollution into the air • A factory puts pollution into a nearby lake • The temperature of the artic increases and the ice flows melt • A forest is cut down to make room for a new city • A strangling–dog vine seed is brought to a field on the socks of a hiker • A lake is over fished until there are no bass left in the lake • Over-fishing of cod in the ocean reduces the population to a level that is not sustaining • Fertilizer from a golf course is washed into a river by the rain • A farmer uses the water from a stream that flows through his field to irrigate his crops